The Azerbaijani socio-political figure, head of Azerbaijan National Council and Musavat Party, Mammad Emin Rasulzadeh, has played a significant role in developing the national liberation movements and as well as realization of its concept in the South Caucasian region in the early 1900s. Especially during the First World War and after the collapse of the Tsarist Russian Empire, as a party leader and an editor of the newspaper, he did important work towards to be met the demands of the nations of the South Caucasus and the Muslims of Russia from the request of autonomy to the implementation of the independent state. After the Soviet Russian occupation of the Azerbaijan Democratic Republic, Mammad Emin Rasulzadeh continued his activities in Europe and wrote his thoughts about republicanism ideology in his published books and articles. This article studies such ideas as republicanism, musavatism and solidarism in the activities and works of Mammad Emin Rasulzadeh.